Piperidine compound



- ance with theprocesses disclosed in United .States Patent No. 2,090,068, and German Patent "No. 637,385. When the starting materials constarting materials, but their action differs from Patented Mar-21, 1939 PATENT;

orr es o BIPERIDINE COMPOUND Ernst Preiswerkplvlunchenstein, near Basel, and

Otto Schnider, Basel, Switzerland, assignorsto Hofi'manmLa' Roche Inc., Nutley, N. J., a corporation of New Jersey ,No Drawing; Application June 29, 1938,

- Serial No. 216,624

5 Claims. (01. 269-2 93 "This invention relates to a new class of com pounds which may be designated as the dior tri-alkyl substituted 2,4-dioxo-piperidines having the following general formula:

I R OO---CH2 wherein R and R" represent alkyl radicals which may be the sameor difierent, and R prepresents either hydrogen or alkyl radicals.

These compounds are prepared by the hydrogenation, preferably catalytic, of compounds having the following generalformula:

.1 in which R and R," represent saturated or unsaturated alkyl radicals which may be the same or diffe'rent, and R may be hydrogen or alkyl.

Such starting materials are prepared in accordtain unsaturated alkyl groups these are hydrogenated simultaneously with the hydrogenation of the carbon atoms of the nucleus.

. 'The new compounds are colorless compounds which may either be oily or solid. Their solubility in water is greater than that of the correvery easily dissolved in water. new compounds are easily soluble in organic spending starting material, some of them being Generally the solvents. Some of them may be distilled under vacuum without decomposition.

' Thenew compounds induce sleep as do the that of the corresponding starting materials in that the sleep inducedthereby lasts longer and, -that the sleep is a little deeper.

v The following examples serve to illustrate the new class of compounds by way of specific example, but the invention is in no way limited thereby.

Example 1 167 parts by weight of 2,4-dioxo-3,3-diethyltetrahydropyridine are dissolved in 600 parts by weight, of methanol. This solution is hydrogenated in the presence of a palladium catalyst which consists of 1 part by weight of finely d1".

"vided metallic palladium precipitated on 9 parts by weight of decolorising charcoal, at a gauge pressure of about A; atmosphere and room temperature with thorough agitation. After a short time 2 parts by weight of hydrogen are assimilated. The resulting solution is separated from 5 the catalyst by filtration and the methanol is distilled off, leaving 2,4-dioxo-3,3-diethyl-piperidine. The product is then recrystallized from a mixture of benzol and. petroleum ether. The pure product has a melting point of l04-105 C. and is quite easily dissolved in water.

Example 2 A solution of 209 parts by weight of l-methyl- 2,4-dioxo-3,3-di-n-propyl-tetrahydropyridine in 520 parts of alcohol is mixed with a nickel catalyst which contains 15 parts by weight of nickel and which is prepared in accordance with the instructions given in Berichte der Deutschen Chemischen Gesellschaft, vol. 49 (1916) pages 55 and 60. This mixture is hydrogenated at 80 C. and 15 atmospheres pressure. The assimilation of hydrogen ceases after a few minutes. The pure product 1-methyl-2,4-dioxo-3,3-di-npropyl-piperidine is obtained by filtering off the catalyst, distilling off the solvent, and then distilling off the product at about 14 mm. pressure and at temperatures between 157 C. and 159 C. The oily substance which distills off crystallizes into a mass melting at 41-42 C.

Example 3 A solution of 181 parts by weight of l-methyl- 2,4-dioxo-3,3-diethyl-tetrahydropyridine in 420 parts by Weight of methanol is hydrogenated in the presence of a palladium catalyst as described in Example 1. The l-methyl-2,4-dioxo-3,3-diethyl-piperidine, which is obtained, is fluid at room temperatures and may be distilled at reduced pressure (boiling point at about 14 mm. being 145-146 0.). The product is also very easily dissolved in water.

Example 4 peridine may be obtained by the hydrogenation of the corresponding tetrahydropyridine compound by methods such as describeddnI thetpreceding examples.

We claim: 1. A compound of the general formula R oo "c'Hl \C/ CHz BK 0 ON wherein R and R represent lower unsubstituted saturated alkyl radicals and R' is selected from the group consisting of hydrogen and lower un substituted saturated alkyl radicals.

2. A compound of the general formula wherein R and R: represent lower unsubstituted saturatedalkyl radicals.

' 3. 2g4+dioxo3g3-diethyl-piperidine.

4. .l-methyl2,4edioxo-3,3-di-n-propyl piperidine.

*5. 1-methy1-2A-dioxo-3,3-diethyl-piperidine.

ERNST PREISWERK. O'I'IO SCHNIDER. 

